The present invention relates to a hand-held electronically-controlled drawing and writing instrument which provides electronic control of the width and pattern of the marks made by the device. More particularly it relates to such a device using ink jet technology to provide a writing instrument.
There exist various writing instruments including ballpoint pens, fibre tip pens, pencils, fountain pens, etc., which allow lines to be drawn to form letters and images. If a different width of line is required, a different pen must be used. If the darkness of the line must be changed, a different pen or ink must be used. The user needs manual dexterity to create patterns, letters, or textures. In addition, conventional instruments rely on contact between the ink delivery device and the substrate for the transfer of ink to the substrate. Constraining the ink delivery device to touch the substrate compromises the number of features and level of performance that can be achieved.
U.S. Pat. No. 4,746,936 describes a pen using an ink jet nozzle to allow completely non-contact marking of surfaces, where the roughness or softness of the surface makes conventional contact marking difficult. The delivery of ink is controlled by a finger-operated switch mounted on the side of the pen. This tackles the problem of writing on difficult surfaces, but does not provide a means of producing high quality writing and drawings with the natural action of sliding a writing instrument over a surface.
The present invention has been devised to overcome the drawbacks of existing marking instruments and to provide features and benefits that have not been possible using conventional techniques.